Misfire Table Tuning

[kyphur]

Does anyone have a good breakdown on the misfire table tuning? I know with a cam with a lot of overlap this table needs to be modified if you enable your MAF. I was just wondering if anyone had a good tutorial.

[Kyne]

I just add 10% until it seems to not set a code and I watch the misfire counts on the scanner. I don't have any empirical way though.

[kyphur]

Yeah, but with a large cam you usually will have misfires showing up unless you go into the diagnostics and effect that table.

This is what I hate about HP Tuners. There's sections of the manual that are just empty. Then you come here to find information and there will be 20+ threads and each one is different in their information. Some are drastically wrong but cite themselves as gospel. Then everything is spoken from an engineer's point of view when people try to explain it. Then you have the tuners who don't want to share information because their tips and tricks are their bread and butter.

Guh...

[umrjmac]

The manual is there to teach you what the tables and values are, not necessarily how to change them for various situations. If you are looking for print documentation there are a couple of options, but they can be pricey. Greg Banish has a couple of books and DVDs and the Tuning School has a couple of learn at home courses. Having said that, I do not know that you will get an answer to your specific question through some or all of that material, but it is an option for sure. I own all of Banish's stuff and the tuning school courses should arrive Tuesday. While its expensive, I consider educating myself cheap insurance against a boneheaded move that would be much more expensive in the end.

You're right in that you may find 5 different answers to the same question. That is the nature of doing your research on forums. There are some industry experts here, some professional tuners, a lot of people who own the product and have varying levels of education on how to calibrate, and people who are just starting out. When estimating value of a response that I find, I tend to put more trust in an answer from a known expert or professional tuner. For people that I do not recognize I check post count, look at other information that they've provided, etc. to establish their relative level of expertise. There is not a one size fits all way to know whether something you read on the internet is true, unfortunately. The people here are very helpful, especially when there is a specific question or problem...something tighter in scope than "How do I adjust the misfire table", but your responses will ultimately be limited by who reads your thread and who has time to respond. This is all volunteer work

On to the meat of the limited amount of advice that I can provide. For what its worth, how the PCM works in your car is not specific to HPTuners, exact information is more about your PCM than the tuning product. The table and field names may be different, but tuning applications expose the same parts of the PCMs programming to you. How misfire tables are used, generally speaking, isn't necessarily specific to your PCM either. If you are looking for technical info about how to approach a problem, I would broaden my search beyond the scope of just this forum. I would check competing product forums, corvetteforum, ls1tech, etc. Non-tuning forums will be hit or miss, but you might find the nugget that you're looking for. Once you have a good baseline understanding, then you should be in a position to validate your understanding with people here and/or narrow the scope of your search to ensure that you are on the right track.

Finally you have the ability to experiment with and validate the information that you find. Make small changes, log the effect, and react based on what the outcome is. When you find the answer to your question, please be sure to reply to your thread with that information so that the research end of things is a little bit easier for the next guy in your shoes.

Have a good one, man.

[kyphur]

Thank you for the response.

I work for a department of defense contractor and help make training for various items that the U.S. military use. Our SME's (Subject Matter Experts) and writers would be fired in a second for letting a manual out that's 1/10th as incomplete as HP Tuner's is. Plus, the support is pretty horrible with a tech popping into threads with a brief response and never commenting again, sometimes making the situation even more confusing.

A good example is with transient fueling. That section of the manual has no information whatsoever in it. Plus, you will find a number or different posts that speculate on what "minimum fuel milligrams" is. A number of posts will cite it as a timed reference period, an fuel mass adder for pulse width, etc., etc.

It's just annoying and knowing how software is developed it would seem that as they break down information given to them so they can actually write the program that they would document it. There are NUMEROUS tables that cross reference each other throughout the interface and you have no idea which ones those are. You could alter one that throws out another table completely and you'll be chasing your tail for days.

While I agree, educating yourself on your own time is an investment. It is, but when you have misinformation fed to you from a non-vested source it can become a nightmare. Especially when the non-vested sources are the only ones responding.

[SSUte01]

I think you guys are being a little hard on HPTuners. If they were to provide what you're suggesting they should you'd be paying many thousands for the privilege. There are hundreds or OSs and thousands of calibrations to reverse engineer into layman speak and define. To provide the detailed what and how for each bit of code without any insight from the engineers that wrote it is a mammoth task nigh on impossible. I see that what HPT provides is access to most of the calibration laid out in decimal English and we should be grateful for that. I know its helping, but the best we can do is empirically test and share info to figure the how. I think what we get for the money we pay, i.e. less than 10K in my case over the years over many OS and cals is tremendous value. It's not easy, if it were, we wouldn't need other pros to do the leg work for us.